The present invention relates to a copier, facsimile apparatus, printer or similar image forming apparatus and more particularly to a digital image forming apparatus.
A copier, printer, facsimile apparatus or similar image forming apparatus capable of forming images in accordance with digital image data is conventional. A current trend in the imaging art is toward a digital image forming apparatus including a memory, hard disk or similar storage for dealing with a great amount of data or for implementing versatile functions. The storage allows, e.g., a facsimile apparatus to receive data even when the apparatus runs out of paper or allows a copier to rotate, when a document and a paper to be deal are different in orientation, its image forming device on the basis of the orientation of the paper.
However, the conventional digital image forming apparatus with the above storage processes each data stored in the storage as independent data and does not link or otherwise associate them together. Although a combination copy mode is available with a modern digital copier for associating a plurality of different data, it simply writes data representative of two documents in the storage and then prints them out while superposing images. This brings about a problem that when images are present at the same positions on two documents, they are superposed on each other and render the resulting copy unusable.